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gotoman for ac
gotoman for ac, HVAC Technician
Category: HVAC
Satisfied Customers: 5163
Experience:  51 years of experience install design and repair of all makes and models of AC
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tempstar model 9000 freezing up looks like a block of ice

Resolved Question:

tempstar model 9000 freezing up looks like a block of ice what controls or relay are used for defrost cycle i live in phoenix az temp this morning was 36 degrees
Submitted: 7 years ago.
Category: HVAC
Expert:  gotoman for ac replied 7 years ago.

Do you have emergency heat. The tempstar uses on demand defrost. When the unit accumulates enough running time after defrost switch is made it goes into defrost. This set at 30 60 90 minutes of accumulative run time. To answer your question both a combination of defrost switch and defrost board. reasons for iceing are bad defrost switch,bad defrost board ,low on gas ,outside fan not shutting of in defrost. Do not hit accept till you are satified with my answer. Good feedback is always welcome. Rus

Customer: replied 7 years ago.
fan is not shutting off what controls it relay ? timer ? etc
Expert:  gotoman for ac replied 7 years ago.
The fan goes thru defrost board The fan only shuts off when it goes into defrost. Rus
Customer: replied 7 years ago.
what sensor tells the defrost board to defrost ?
Expert:  gotoman for ac replied 7 years ago.
There is a sensor attatched to the condensor, The condensor becomes evaporater in the winter time.The sensor senses the temp when the temp goes bellow 32 degrees and sends a signal to the defrost board and it starts to accumulate running time. When the running accumualtes 30 60 90 minutes depending where the defrost pins are set on the defrost board. It will go into defrost and run until the sensor measures about 80 to 90 degrees or 10 minutes of continuous defrost. You can change the duration of defrost by setting these pins to different times. Rus
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